Method for detecting trace acid insoluble substances in raw material silicon powder for polycrystalline silicon
By cleaning the crucible with high-purity water and heating and acid washing, combined with mixed acid digestion and dilution steps, the problem of inaccurate detection of trace acid-insoluble matter in industrial silicon powder was solved, and higher detection accuracy was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-03
AI Technical Summary
Existing technologies cannot accurately detect trace amounts of acid-insoluble matter in industrial silicon powder, especially when the amount is below 0.2%, leading to inaccurate test results.
The crucible is cleaned with high-purity water and heated for acid washing. The silicon powder sample is digested with mixed acid, and the sample is diluted and filtered to ensure that the acid-soluble substances in the crucible are removed, thereby avoiding errors and improving the accuracy of the test.
By processing the crucible and dilution steps, trace amounts of acid-insoluble matter in industrial silicon powder can be accurately detected, solving the problem of inaccurate detection and improving the accuracy of detection.
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Figure CN121783760A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material silicon powder, belonging to the technical field of detecting trace amounts of acid-insoluble matter in industrial silicon powder. Background Technology
[0002] Currently, one of the raw materials used in polysilicon production is industrial silicon powder. The detection of trace acid-insoluble matter in industrial silicon powder is carried out according to YS / T~724~2016. When the trace acid-insoluble matter in industrial silicon powder is less than 0.2%, the YS / T~724~2016 method cannot accurately detect it, and no solution has yet been found in the existing technology to solve the above technical problem. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method for detecting trace acid-insoluble matter in polycrystalline silicon raw material silicon powder, which can solve the problem that trace acid-insoluble matter in industrial silicon powder cannot be accurately detected, and can be used to detect trace acid-insoluble matter in industrial silicon powder when the amount is less than 0.2%.
[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:
[0005] A method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material powder includes the following steps:
[0006] Step a: After cleaning the crucible with high-purity water, place the entire crucible in hydrochloric acid solution and then heat and acid wash it.
[0007] Step b: After heating and acid washing, rinse the crucible with running high-purity water, and then place the crucible on a vacuum filtration device for vacuum filtration with high-purity water.
[0008] Step c: After filtration, place the crucible in an electric constant temperature drying oven for drying, then cool and weigh it. Repeat the above process until the mass is constant to obtain the acid-washed crucible.
[0009] Step d: Add the industrial silicon powder sample to a beaker, place the beaker in a fume hood, add a small amount of water to wet it, and slowly add a mixture of hydrofluoric acid and nitric acid along the beaker wall to completely digest the industrial silicon powder sample.
[0010] Step e: After digestion, place the beaker on a heating plate and heat until the liquid completely evaporates to obtain dry solid salts. Then add hydrochloric acid solution to completely dissolve the solid salts.
[0011] Step f: Transfer the dissolved sample to a clean container, dilute it with hot water, and filter it while hot into a crucible that has been acid-washed. After filtration, filter it again with hot water until there are no chloride ions in the filtrate.
[0012] Step g: Place the filtered crucible in an electric thermostatic drying oven to dry, then place it in a desiccator to cool to room temperature, weigh it, and repeat the above process until the mass is constant.
[0013] In step a, the crucible is a glass frit crucible; the hydrochloric acid solution is prepared by mixing high-purity water with 36-38% hydrochloric acid by mass at a volume ratio of 1:1; the temperature for acid washing is 50°C and the time is 30 minutes.
[0014] In step b, the high-purity water is used for rinsing 10 times; the volume of high-purity water used for filtration is 500 mL, and the temperature is not lower than 80℃.
[0015] In step c, the drying temperature in the electric heating constant temperature drying oven is 105±2℃; the standard for judging constant quality is that the difference between the two consecutive weights is no more than 0.0003g.
[0016] In step d, the mixed acid of hydrofluoric acid and nitric acid is prepared by mixing superior pure hydrofluoric acid with a mass fraction of ≥40% and superior pure nitric acid with a mass fraction of 65~68% at a volume ratio of 2:1.
[0017] In step e, the heating plate is heated to 200°C, and the hydrochloric acid solution is prepared by mixing high-purity hydrochloric acid with a mass fraction of 36-38% and high-purity water in a volume ratio of 1:1.
[0018] In step f, hot water dilution uses 500 mL of hot water at a temperature not lower than 80°C; hot water filtration uses 300 mL of hot water at a temperature not lower than 80°C.
[0019] Chloride ions in the filtrate were detected using a 17 g / L silver nitrate solution.
[0020] In step g, the drying temperature of the electric thermostatic drying oven is 105±2℃.
[0021] The criterion for judging constant quality is that the difference between two consecutive weight measurements is no greater than 0.0003g.
[0022] The method for calculating trace amounts of acid-insoluble matter is as follows:
[0023] ;
[0024] Where W represents the mass content of acid-insoluble matter, in %, m1 represents the sum of the mass of the crucible and the mass of acid-insoluble matter after the mass is constant in step g, in g, m2 represents the mass of the crucible after acid washing treatment in step c, in g, and m represents the mass of the industrial silicon powder sample in step d, in g.
[0025] The beneficial effects of this invention are as follows: This invention provides a method for detecting trace acid-insoluble matter in polycrystalline silicon raw material silicon powder. After cleaning the crucible with high-purity water, the entire crucible is placed in a hydrochloric acid solution and heated for acid washing. After acid washing, the crucible is rinsed with flowing high-purity water, and then placed on a vacuum filtration device for high-purity water filtration. This pretreatment of the crucible removes acid-soluble matter from the crucible, preventing the retention of acid-insoluble matter in the silicon powder during subsequent acid insoluble matter measurements. This would incorrectly compensate for the weight of acid-soluble matter in the crucible, leading to inaccurate measurements and the inability to accurately detect low concentrations of acid-insoluble matter. Therefore, this invention solves the problem of inaccurate detection of trace acid-insoluble matter in industrial silicon powder and can be used to detect trace acid-insoluble matter in industrial silicon powder below 0.2%. The dissolved sample is transferred to a clean container and diluted with hot water. By diluting the salts, the corrosion and weight loss of the sand core crucible by fluoride ions are avoided, further increasing the accuracy of trace acid-insoluble matter detection. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the digestion, dilution, and filtration process of the present invention;
[0027] The figures are labeled as follows: 1-PFA beaker; 2-heating plate; 3-container; 4-G4 glass frit crucible; 5-filter flask; 6-vacuum pump. Detailed Implementation
[0028] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.
[0029] Example 1
[0030] This invention discloses a method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material silicon powder, using 99% industrial silicon powder for analysis, specifically including the following steps:
[0031] Step 1: Clean the 30mL-G4 glass frit crucible (hereinafter referred to as the crucible) with high-purity water and place it in a 1+1 hydrochloric acid solution (preparation method: mix 36~38% analytical grade hydrochloric acid and high-purity water at a volume ratio of 1:1). The hydrochloric acid level in the container should be greater than 1 times the height of the crucible. The container can be a glass or PFA beaker. After immersing the crucible in the 1+1 volume concentration hydrochloric acid solution, place the container on a heating plate and heat it at 50℃ for 30 minutes. This allows the hydrochloric acid to dissolve the metal oxides, carbonates, and other inorganic impurities on the surface of the crucible, avoiding the influence of batch differences on the results.
[0032] Step 2: Rinse the crucible 10 times with running high-purity water. Place the crucible on a vacuum filtration device and use 500mL of high-purity water at a temperature not lower than 80℃ to filter the crucible. It will take about 5 minutes to complete the filtration of 500mL of hot water, thus cleaning the residual hydrochloric acid on the sand core inside the crucible.
[0033] Step 3: Place the crucible in an electric thermostatic drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in the desiccator, weigh it, and repeat step 3 until the weight is constant (the difference between the two weights is no more than 0.0003g). Record this as m2, which is 28.5060g.
[0034] Step 4: Weigh approximately 1.0000g (accurate to 0.0001g) of industrial silicon powder sample, denoted as m, specifically 1.0038g, into a PFA beaker. Place the beaker in a fume hood, moisten it with a small amount of water, and slowly add HF:HNO3 = 2:1 mixed acid (preparation method: prepared by mixing superior grade hydrofluoric acid with a mass fraction ≥40% and superior grade nitric acid with a mass fraction of 65~68% in a volume ratio of 2:1) along the beaker wall. Approximately 12mL can completely digest the sample.
[0035] Step 5: Place on a 200℃ heating plate and heat until the liquid completely evaporates to obtain a dry solid. Add 5mL of (1+1) hydrochloric acid solution (preparation method: prepared by mixing 36~38% mass fraction of superior pure hydrochloric acid and high-purity water at a volume ratio of 1:1) to completely dissolve the salts.
[0036] Step Six: Transfer the dissolved sample to a clean container (capacity not less than 500 mL), dilute it with 500 mL of hot water at a temperature not lower than 80°C, and filter it while it is still hot into the crucible treated in Steps One to Three. After filtration, filter it again with 300 mL of hot water at a temperature not lower than 80°C until there are no chloride ions in the filtrate (tested with 17 g / L silver nitrate solution).
[0037] The operation diagrams for the digestion in step four and the dilution and filtration in step six are as follows: Figure 1 As shown. Digestion was performed using a PFA beaker (1) and a heating plate (2), dilution was performed using a 500 mL container (3), and filtration was performed using a 30 mL G4 glass frit crucible, a filtration flask (5), and a vacuum pump (6).
[0038] Step 7: Place the crucible in an electrically heated constant temperature drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in a desiccator and weigh it. Repeat step 7 until a constant weight is achieved, and record it as m1, which is 28.5078 g.
[0039] The method for calculating trace amounts of acid-insoluble matter is as follows:
[0040] ;
[0041] Where W represents the mass content of acid-insoluble matter, in percentage, the calculated acid-insoluble matter content is 0.18%.
[0042] Example 2
[0043] This invention discloses a method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material silicon powder, using 99% industrial silicon powder for analysis, specifically including the following steps:
[0044] Step 1: Clean the 30mL-G4 glass frit crucible (hereinafter referred to as the crucible) with high-purity water and place it in a 1+1 hydrochloric acid solution (preparation method: mix 36~38% analytical grade hydrochloric acid and high-purity water at a volume ratio of 1:1). The hydrochloric acid level in the container should be greater than 1 times the height of the crucible. The container can be a glass or PFA beaker. After immersing the crucible in the 1+1 volume concentration hydrochloric acid solution, place the container on a heating plate and heat it at 48℃ for 32 minutes. This allows the hydrochloric acid to dissolve the metal oxides, carbonates, and other inorganic impurities on the surface of the crucible, avoiding the influence of batch differences on the results.
[0045] Step 2: Rinse the crucible 10 times with running high-purity water. Place the crucible on a vacuum filtration device and use 500mL of high-purity water at a temperature not lower than 80℃ to filter the crucible. It will take about 5 minutes to complete the filtration of 500mL of hot water, thus cleaning the residual hydrochloric acid on the sand core inside the crucible.
[0046] Step 3: Place the crucible in an electric thermostatic drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in the desiccator, weigh it, and repeat step 3 until the weight is constant (the difference between the two weights is no more than 0.0003g). Record this as m2, which is 28.4881g.
[0047] Step 4: Weigh approximately 1.0000g (accurate to 0.0001g) of industrial silicon powder sample, denoted as m, specifically 1.0145g, into a PFA beaker. Place the beaker in a fume hood, moisten it with a small amount of water, and slowly add HF:HNO3 = 2:1 mixed acid (preparation method: prepared by mixing superior grade hydrofluoric acid with a mass fraction ≥40% and superior grade nitric acid with a mass fraction of 65~68% in a volume ratio of 2:1) along the beaker wall. Approximately 12mL can completely digest the sample.
[0048] Step 5: Place on a 200℃ heating plate and heat until the liquid completely evaporates to obtain a dry solid. Add 5mL of (1+1) hydrochloric acid solution (preparation method: prepared by mixing 36~38% mass fraction of superior pure hydrochloric acid and high-purity water at a volume ratio of 1:1) to completely dissolve the salts.
[0049] Step Six: Transfer the dissolved sample to a clean container (capacity not less than 500 mL), dilute it with 500 mL of hot water at a temperature not lower than 80°C, and filter it while it is still hot into the crucible treated in Steps One to Three. After filtration, filter it again with 300 mL of hot water at a temperature not lower than 80°C until there are no chloride ions in the filtrate (tested with 17 g / L silver nitrate solution).
[0050] The operation diagrams for the digestion in step four and the dilution and filtration in step six are as follows: Figure 1 As shown. Digestion was performed using a PFA beaker (1) and a heating plate (2), dilution was performed using a 500 mL container (3), and filtration was performed using a 30 mL G4 glass frit crucible, a filtration flask (5), and a vacuum pump (6).
[0051] Step 7: Place the crucible in an electrically heated constant temperature drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in a desiccator and weigh it. Repeat step 7 until a constant weight is achieved, and record it as m1, which is 28.4898 g.
[0052] The method for calculating trace amounts of acid-insoluble matter is as follows:
[0053] ;
[0054] Where W represents the mass content of acid-insoluble matter, in percentage, the calculated acid-insoluble matter content is 0.17%.
[0055] Example 3
[0056] This invention discloses a method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material silicon powder, using 99% industrial silicon powder for analysis, specifically including the following steps:
[0057] Step 1: Clean the 30mL-G4 glass frit crucible (hereinafter referred to as the crucible) with high-purity water and place it in a 1+1 hydrochloric acid solution (preparation method: mix 36~38% analytical grade hydrochloric acid and high-purity water at a volume ratio of 1:1). The hydrochloric acid level in the container should be greater than 1 times the height of the crucible. The container can be a glass or PFA beaker. After immersing the crucible in the 1+1 volume concentration hydrochloric acid solution, place the container on a heating plate and heat it at 52℃ for 28 minutes. This allows the hydrochloric acid to dissolve the metal oxides, carbonates, and other inorganic impurities on the surface of the crucible, avoiding the influence of batch differences on the results.
[0058] Step 2: Rinse the crucible 10 times with running high-purity water. Place the crucible on a vacuum filtration device and use 500mL of high-purity water at a temperature not lower than 80℃ to filter the crucible. It will take about 5 minutes to complete the filtration of 500mL of hot water, thus cleaning the residual hydrochloric acid on the sand core inside the crucible.
[0059] Step 3: Place the crucible in an electric thermostatic drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in the desiccator, weigh it, and repeat step 3 until the weight is constant (the difference between the two weights is no more than 0.0003g). Record this as m2, which is 28.7032g.
[0060] Step 4: Weigh approximately 1.0000g (accurate to 0.0001g) of industrial silicon powder sample, denoted as m, specifically 1.0056g, into a PFA beaker. Place the beaker in a fume hood, add a small amount of water to moisten it, and slowly add HF:HNO3 = 2:1 mixed acid (preparation method: prepared by mixing superior grade hydrofluoric acid with a mass fraction ≥40% and superior grade nitric acid with a mass fraction of 65~68% in a volume ratio of 2:1) along the beaker wall. Approximately 12mL can completely digest the sample.
[0061] Step 5: Place on a 200℃ heating plate and heat until the liquid completely evaporates to obtain a dry solid. Add 5mL of (1+1) hydrochloric acid solution (preparation method: prepared by mixing 36~38% mass fraction of superior pure hydrochloric acid and high-purity water at a volume ratio of 1:1) to completely dissolve the salts.
[0062] Step Six: Transfer the dissolved sample to a clean container (capacity not less than 500 mL), dilute it with 500 mL of hot water at a temperature not lower than 80°C, and filter it while it is still hot into the crucible treated in Steps One to Three. After filtration, filter it again with 300 mL of hot water at a temperature not lower than 80°C until there are no chloride ions in the filtrate (tested with 17 g / L silver nitrate solution).
[0063] The operation diagrams for the digestion in step four and the dilution and filtration in step six are as follows: Figure 1 As shown. Digestion was performed using a PFA beaker (1) and a heating plate (2), dilution was performed using a 500 mL container (3), and filtration was performed using a 30 mL G4 glass frit crucible, a filtration flask (5), and a vacuum pump (6).
[0064] Step 7: Place the crucible in an electrically heated constant temperature drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in a desiccator and weigh it. Repeat step 7 until a constant weight is achieved, and record it as m1, which is 28.7051 g.
[0065] The method for calculating trace amounts of acid-insoluble matter is as follows:
[0066] ;
[0067] Where W represents the mass content of acid-insoluble matter, in percentage, the calculated acid-insoluble matter content is 0.19%.
[0068] Comparative Example 1
[0069] This comparative example uses 99% of the industrial silicon powder from Example 1 for analysis, specifically including the following steps:
[0070] Step 1: After rinsing the new crucible with high-purity water, place it in an electric thermostatic drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in the desiccator, weigh it, and repeat the operation until the weight is constant (the mass difference is not greater than 0.0003g), and record it as 28.9549g.
[0071] Step 2: Weigh 1.0383 g of the sample into a PFA beaker, add a small amount of water to moisten it, and slowly add HF:HNO3=2:1 mixed acid (about 12 mL) along the beaker wall until the sample is completely digested.
[0072] Step 3: After heating on a 200℃ heating plate until dry, add 5mL (1+1) hydrochloric acid to completely dissolve the salts.
[0073] Step 4: While still hot, filter the solution into the crucible treated in Step 1, and filter with hot water at a temperature not lower than 80°C until no chloride ions are present in the filtrate (tested with 17g / L silver nitrate solution).
[0074] Step 5: Place in an electric thermostatic drying oven and dry at 105±2℃ until the weight is constant. Cool to room temperature in the desiccator and weigh. Repeat step 5 until constant weight is achieved, and record the weight as 28.9552g.
[0075] Step 6: Calculate the acid-insoluble matter content to be 0.03%.
[0076] Comparative Example 2
[0077] This comparative example uses 99% of the industrial silicon powder from Example 1 for analysis, specifically including the following steps:
[0078] Step 1: After rinsing the new crucible with high-purity water, place it in an electric thermostatic drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in the desiccator, weigh it, and repeat step 3 until the weight is constant (the mass difference is not greater than 0.0003g), which is recorded as 28.8813g.
[0079] Step 2: Weigh 1.0017 g of the sample into a PFA beaker, add a small amount of water to moisten it, and slowly add HF:HNO3=2:1 mixed acid (about 12 mL) along the beaker wall until the sample is completely digested.
[0080] Step 3: After heating on a 200℃ heating plate until dry, add 5mL (1+1) hydrochloric acid to completely dissolve the salts.
[0081] Step 4: Transfer the dissolved sample to a clean container (capacity not less than 500 mL), dilute it with 500 mL of hot water at a temperature not lower than 80°C, and filter it while hot into the crucible treated in Step 1. After filtration, filter it again with 300 mL of hot water at a temperature not lower than 80°C until there are no chloride ions in the filtrate (tested with 17 g / L silver nitrate solution).
[0082] Step 5: Place the crucible in an electrically heated constant-temperature drying oven and dry it at 105±2℃ until the mass is constant. Cool it to room temperature in a desiccator and weigh it. Repeat step 7 until a constant weight is achieved, and record the weight as 28.8822g.
[0083] Step 6: Calculate the acid-insoluble matter content to be 0.09%.
[0084] Comparing the embodiments of the present invention with the comparative examples, it can be seen that the acid-insoluble content calculated by the present invention is much greater than that calculated by the comparative examples. This proves that the present invention removes the acid-soluble substances in the crucible by heating and acid washing the crucible, and dilutes the dried salts to avoid the corrosion and weight reduction of the sand core crucible by fluoride ions, thus solving the problem of inaccurate detection of trace acid-insoluble substances in industrial silicon powder.
[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material silicon powder, characterized in that: Includes the following steps: Step a: After cleaning the crucible with high-purity water, place the entire crucible in hydrochloric acid solution and then heat and acid wash it. Step b: After heating and acid washing, rinse the crucible with running high-purity water, and then place the crucible on a vacuum filtration device for vacuum filtration with high-purity water. Step c: After filtration, place the crucible in an electric constant temperature drying oven for drying, then cool and weigh it. Repeat the above process until the mass is constant to obtain the acid-washed crucible. Step d: Add the industrial silicon powder sample to a beaker, place the beaker in a fume hood, add a small amount of water to wet it, and slowly add a mixture of hydrofluoric acid and nitric acid along the beaker wall to completely digest the industrial silicon powder sample. Step e: After digestion, place the beaker on a heating plate and heat until the liquid completely evaporates to obtain dry solid salts. Then add hydrochloric acid solution to completely dissolve the solid salts. Step f: Transfer the dissolved sample to a clean container, dilute it with hot water, and filter it while hot into a crucible that has been acid-washed. After filtration, filter it again with hot water until there are no chloride ions in the filtrate. Step g: Place the filtered crucible in an electric thermostatic drying oven to dry, then place it in a desiccator to cool to room temperature, weigh it, and repeat the above process until the mass is constant.
2. The method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: In step a, the crucible is a glass frit crucible; the hydrochloric acid solution is prepared by mixing high-purity water with 36-38% hydrochloric acid by mass at a volume ratio of 1:1; the temperature for acid washing is 50°C and the time is 30 minutes.
3. The method for detecting trace acid-insoluble substances in polycrystalline silicon raw material silicon powder according to claim 1, characterized in that: In step b, the high-purity water is used for rinsing 10 times; the volume of high-purity water used for filtration is 500 mL, and the temperature is not lower than 80℃.
4. The method for detecting trace acid-insoluble matter in polycrystalline silicon raw material silicon powder according to claim 1, characterized in that: In step c, the drying temperature in the electric heating constant temperature drying oven is 105±2℃; the standard for judging constant quality is that the difference between the two consecutive weights is no more than 0.0003g.
5. The method for detecting trace acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: In step d, the mixed acid of hydrofluoric acid and nitric acid is prepared by mixing superior pure hydrofluoric acid with a mass fraction of ≥40% and superior pure nitric acid with a mass fraction of 65~68% at a volume ratio of 2:
1.
6. The method for detecting trace acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: In step e, the heating plate is heated to 200°C, and the hydrochloric acid solution is prepared by mixing high-purity hydrochloric acid with a mass fraction of 36-38% and high-purity water in a volume ratio of 1:
1.
7. The method for detecting trace acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: In step f, hot water dilution uses 500 mL of hot water at a temperature not lower than 80°C; hot water filtration uses 300 mL of hot water at a temperature not lower than 80°C.
8. The method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material powder according to claim 7, characterized in that: Chloride ions in the filtrate were detected using a 17 g / L silver nitrate solution.
9. The method for detecting trace amounts of acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: In step g, the drying temperature of the electric thermostatic drying oven is 105±2℃. The criterion for judging constant quality is that the difference between two consecutive weight measurements is no greater than 0.0003g.
10. The method for detecting trace acid-insoluble matter in polycrystalline silicon raw material powder according to claim 1, characterized in that: The method for calculating trace amounts of acid-insoluble matter is as follows: ； Where W represents the mass content of acid-insoluble matter, in %, m1 represents the sum of the mass of the crucible and the mass of acid-insoluble matter after the mass is constant in step g, in g, m2 represents the mass of the crucible after acid washing treatment in step c, in g, and m represents the mass of the industrial silicon powder sample in step d, in g.